This invention relates to liquid aerators of the type which are used to prevent water stagnation, to enrich the oxygen content of water to scrub waste from water or to cool water for recirculation. Such aerators usually comprise a multi-bladed axial flow impeller power-rotated by an electric motor and operable to pump water upwardly through a throat. At the upper end of the throat, the water is deflected outwardly for interface contact with the surrounding air prior to falling back into the body of water.